CheatsPower of Love - The Sword you get when you fight Gideon (offline only)
At the main menu, input . You will hear an audio confirmation.
With this code input, you will start each round with the Power of Love sword. This should make your playthrough with Wallace quick and easy.

ExploitsInfinite Money & Experience (Requires two controllers)
Doing this will allow you to start out as a fully leveled, fully upgraded character with 9 lives.
What you need to do is have the player you want to upgrade selected by player 1 (in the case of this DLC, it should most likely be Wallace Wells), and whichever player you have with the most money selected by player 2, using a Guest Profile. Next, you should start a stage and make your way to the closest shop. Then just proceed to lend all of the money from player 2 to player 1 (have player 2 stand on player 1 and hold until all of their money transfers to player 1). Press and Return to map, this will save the money player 1 has. Then you can quit. If necessary, rinse and repeat until player 1 has ~$750. Next, you can play with just one controller and head to the shopping district (Stage 1.5) and enter the video store. Pay Scott's Late Fees of ~$500 and you will get a selection of movies for $4.95 each:

To get this trophy, simply complete one stage online with any character. It does not even have to be a complete stage, you can pick Stage 1.5 for instance (Shopping District) and only do half a stage. It just has to end with beating a boss.

Note: Although you can pick anyone, it is recommended you choose from the 5 characters (Scott, Kim, Stills, Ramona, and Wallace) needed for Everybody wants to play.

Everybody wants to playPlayed Online with all characters at least once (including Wallace Wells)

To attain this trophy you must finish a stage online with each of the 4 main characters (Scott, Kim, Stills, and Ramona) as well as with Wallace.
The hardest part of this trophy is actually finding an online session to join. From my quick experience with it, it seemed easier to create my own and wait for someone to join. Also, when creating your own session, you can select what stage to start on. I chose Stage 3.5 for the most part as there are a lot of enemies, so I could progress toward Wallaciraptor! faster.

You do not need to complete a stage with Knives or with Negascott.

With lag being a major issue in this game's online portion, it is probably best to stick to 2 player matches, rather than 3 player or 4 player. Also, it will be a lot easier to actually find a match if you only need 1 player other than yourself.

And... It's a Wrap!Clear the game once with Wallace Wells

Take advantage of the Cheats & Exploits Section by fully leveling and upgrading Wallace. Then blow through the game with the Power of Love sword in hand. You can play on Average Joe difficulty making this even easier. This whole process should take you about an hour.

However, if you want to play "fairly" and not use cheats or exploits... Then simply play through the entire game you have most likely already played several times before with Wallace and once you beat Gideon, this trophy will be yours.

To get this trophy you will need a total of 200 knockouts across all of your online matches. Since you need to play a stage with 5 different characters for Everybody want to play, this should unlock naturally as you progress toward that trophy. At the end of each stage it tells you how many KO's you got, and how many your co-op partner(s) got. Only your KO's count toward this trophy. If you do not have enough KO's after you unlock Everybody want to play, then simply play another stage until it unlocks.